KVM (keyboard, video and mouse) is a technology that allows remote control of a managed machine from another terminal or personal computer (PC). There are analog KVM switches that connect a remote terminal, keyboard and mouse (herein a remote console) to one of several PCs such that the KVM signals are switched and a single PC is controlled at a given time. Such switches are typically analog switches and are limited in the distance between the managed machine, and the console typically includes a graphics screen.
Another technology that allows a remote control from a larger distance is KVM over internet protocol (IP), also referred to as KVM redirection. This technology samples the analog signals of the screen into a frame buffer and relays the compressed frame buffer to a remote console where viewer software shows the captured screen content. Similarly, keyboard and mouse controls are sent through the network to the managed machine. The KVM hardware includes an analog-to-digital (A/D) converter if it supports analog video sampling or includes a serial digital output capture circuit.
In order to connect to the external graphics card's output signals as described above, a special connector or wiring has to be connected, and special input analog pins at the KVM system have to be added. Sometimes if the KVM system does not support analog signals, an external A/D chip has to be added to the solution, increasing cost and complexity.